In stacking bags or the like comprising the "quick-opening" or satchel type bag having closed bottom ends that are collapsed and folded back over an open ended body portion, the multi-layered bottom ends of a collated stack will build up quicker than the opposite open end portion of the bags. After only a relatively few bags have been collected in a stack, a slope develops which considerably limits the height to which a stable stack can be formed. Further, bags assembled in bundles of non-uniform thickness would be difficult to package or wrap and present storage, handling, and shipping problems.
Accordingly, in bag packaging operations of the past, only comparatively small quantities of bags could be collected in stacks as they were produced by the bag machine which were then usually hand assembled in larger bundles for wrapping with the bottom and top ends of the small stacks arranged at alternate sides to achieve a desired bundle quantity with substantially uniform thickness.
Obviously, hand operations impose a limiting factor in a packaging operation and with the development of new, high production bag manufacturing machines (800 to 1000 bags formed per min.) hand operations can no longer keep up with these production rates. Even with the development of certain pneumatic collating and stacking machines production rates are limited, since at top speeds of operation these machines can handle only about 650 bags per minute while requiring considerable maintenance and using large volumes of compressed air. Accordingly, it would be a decided advance in the state of the art to provide an automatic collating and stacking apparatus which can accommodate these high performance bag machines.